In the display technology field, a scaler, widely applied to a display control apparatus, e.g., a television (TV) or a display, is capable of appropriately scaling images and displayed contents having different resolutions from image sources and displaying the image contents on the display apparatus completely. When a resolution of image content from an image source becomes higher and higher, the resolution needs to be reduced to conform to a display panel having a lower resolution, i.e., the image frame needs to be scaled to conform to the display panel having the lower resolution; however, the resolution of the image content may be undesirably affected, especially content having a high degree of detail, including small characters, may become blurred after having been scaled in this manner.
As multimedia developed, in addition to a personal computer (PC), other types of multimedia devices also serve as image sources of the display apparatus, e.g., a DVD player or video game system. Most players can define output resolutions according to support ability of a transmission interface, but most users are unlikely to adjust the resolutions according to different contents. Therefore, when a resolution of content is different from an output resolution of a player (e.g., the output resolution of the player is 1920×1080 pixels, and the resolution of the content is 1366×768 pixels), the player needs to first scale the content to the output resolution, and then transmit the content to a display end via a transmission interface supporting the output resolution as shown in FIG. 1. However, when the resolution of a panel at the display end is different from the output resolution of the player, the content needs to be scaled again to conform to the resolution of the panel before it is displayed at the display end. Image quality displayed on the resultant panel may be damaged, for example, images may exhibit pixel loss or degradation when the content is scaled multiple times in this manner.
In addition, in applications having three-dimensional (3D) display, a pair of active 3D glasses are turned on and turned off to conform to left and right frames of the display control apparatus to achieve the desired 3D display effect. Since each image frame comprises a data enable (DE) region and a blanking region, in the prior art, the pair of 3D glasses is only turned on during a scan interval corresponding to the blanking region of the image frame after the DE region (i.e., to-be-displayed content) of an image frame is completely displayed in order to properly display the complete display content. When the turn-on time of the pair of 3D glasses is increased, the frame luminance perceived by a user is typically increased. In addition, since a liquid crystal display (LCD) apparatus has a long response time of liquid crystal elements, a long turn-on time of the pair of 3D glasses can stabilize the liquid crystal elements to avoid liquid crystal elements not responding in order to achieve an accurate status before the pair of 3D glasses is turned off. Therefore, the turn-on time of the pair of 3D glasses influences the 3D display effect. However, when the scaler of the display control apparatus downscales an image from a high-resolution image source to the lower resolution of the panel, the blanking region of the image is correspondingly scaled down, so that the turn-on time of the pair of 3D glasses is reduced, which is unbeneficial to the 3D display effect of the display.